SAN FRANCISCO — Spewing magnums of champagne and waving to enthusiastic crowds hoisting New Zealand’s southern cross flags, Emirates Team New Zealand celebrated its challenger series victory over Italy on Sunday and pledged to do its best to wrest the America’s Cup trophy away from the Americans.

“The only reason we’re in San Francisco is to actually take the cup away, as nice of a city as it is,” Grant Dalton, managing director of the New Zealand team, said after the race. “We understand why we’re here.”

Over the course of the best-of-13 Louis Vuitton Cup finals, New Zealand fought heavy winds, breakdowns and a dramatic nose-dive that tossed two crew members into the bay. Sunday, the Kiwis maneuvered through light winds and broke through dense fog to cross the finish line three minutes and 20 seconds ahead of Italy’s Luna Rossa and clinch the series 7-1.

But the big question remains: Can the New Zealand team, funded by the government, an airline and other corporate sponsors, beat the Oracle Team USA powerhouse owned by billionaire Larry Ellison?

“The bottom line is nobody in the know knows,” said John Bertrand, the Australian who broke the Americans’ 132-year hold on the America’s Cup when his Australia II team beat Dennis Conner’s Liberty in 1983. “The next two weeks could be the decider in terms of development. Every time (the teams) go out, they get faster. They improved in speed by 30 percent since they were first launched.”

New Zealand has already proved to be fast in its 72-foot catamaran, setting a racecourse speed record Saturday of 54 mph — about five times faster than traditional monohulls raced in past America’s Cups.

But Dalton, as confident as he is in his boat and his crew, isn’t certain.

“We just don’t really know how fast they are,” Dalton said of Oracle Team USA during a news conference. “Certainly they’re fast. They look at us. We look at them. We shoot each other with radar guns. They’re definitely getting quicker, but we ultimately don’t know.”

With New Zealand heading to the final match next month, the team is hoping to revive the fascination and euphoria it generated back home when it won the cup in 1995 and again in 2000. The first victory was considered by the Kiwis to be the biggest thing to happen to New Zealand since Sir Edmund Hillary conquered Mount Everest.

The Kiwis were crushed, however, when the team lost the trophy in 2003 after their native son Russell Coutts, who had won the cup twice for his homeland, defected to the Swiss team Alinghi. Making for an even more passionate rivalry on San Francisco Bay this year, Coutts is now the CEO of Oracle Team Racing.

Ellison and Coutts chose the high-tech catamarans with 130-foot wing sails for their speed and excitement, hoping that the natural amphitheater of San Francisco Bay and the spectacular TV coverage showcasing the city skyline would draw new fans to the sport.

The regatta has been plagued by troubles, however, from the capsize and resultant death of a crewman on the Swedish Artemis Racing yacht in May, to the low number of teams competing in the challenger series, to allegations that Oracle Team USA cheated by stuffing bags of lead into posts on the smaller boats they raced in the America’s Cup World Series last year.

A jury of international sailing experts has yet to conclude its hearings on the matter, although Oracle Team USA forfeited its trophies from those regatta and called the problem a “mistake.”

The scandal deepened Sunday when the jury released more information, showing that not only did the measuring committee find the added bags of weight on the boats but also that the posts themselves were modified.

The end of the Louis Vuitton Cup means the elimination of Italy’s Luna Rossa, which has been the most fiery, controversial — and stylish — team, owned by fashion house Prada. Not only did the team boycott the first race of the Louis Vuitton Cup in protests of new safety rules it believed were rigged against it, but Luna Rossa also snubbed the Louis Vuitton Cup black-tie party.

New Zealanders, however, are thrilled.

“It’s just a step in the journey to bring the ‘Auld Mug’ home,” Liz TeAmo said of the oldest continuous trophy in sports. She is part of the indigenous Maori people of New Zealand who traveled to San Francisco with a group of friends and draped themselves in New Zealand flags to watch the Louis Vuitton Cup finals. The New Zealand sailors, she said, “all our heroes. They’re ‘whanau,’ our family.”

Julia Prodis Sulek has been a general assignment reporter for the Bay Area News Group, based in San Jose, her hometown, since the late 1990s. She has covered everything from plane crashes to presidential campaigns, murder trials to NBA Finals. In a video that went viral, she captured runners paying tribute to a World War II veteran. Her specialty is narrative storytelling.

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